JPS6050052B2 - Manufacturing method of chip type solid electrolytic capacitor - Google Patents

Description

Detailed Description of the Invention The present invention relates to a method for manufacturing a chip-type solid electrolytic capacitor, and its purpose is to manufacture a chip-type solid electrolytic capacitor that has excellent shape and dimensional accuracy and is suitable for mass production. It is about providing law.

In recent years, as electronic devices have become smaller and thinner and electronic circuits have become more dense, the electronic components used have been required to be smaller and more compact, and even tantalum solid electrolytic capacitors have large capacitance per unit volume and There is a demand for a chip-type device that can be automatically inserted into a circuit board.

Typical conventional capacitors of this type include a resin mold type as shown in FIG. 1A, and a U-shaped terminal type as shown in the opening of the figure. A shows metal pieces 2 at both poles of a solid electrolytic capacitor element 1 on which a semiconductor layer and a conductor layer are formed.
, 3 are connected, they are molded with resin 4, but when resin molding, external force is applied to the capacitor element, which tends to damage the characteristics of the capacitor element, and the proportion of the resin in the total volume is small. It is large and difficult to miniaturize. Another disadvantage is that the resin is easily damaged when the metal pieces 2 and 3 exposed to the outside are bent to form external terminals. For the U-shaped terminal type, a cap-shaped cathode terminal 5 is connected to the cathode of the solid electrolytic capacitor element 1 after forming the semiconductor layer and the conductive layer by conductive adhesive or soldering, and a valve-like material such as tantalum is used. It is formed by welding a U-shaped anode terminal 6 to an anode lead wire made of metal and filling the resin 4 between the element and both terminals. Since the three steps of resin filling are performed sequentially, there is a drawback that productivity is low in mass production. The present invention is intended to provide a method for manufacturing a chip-type solid electrolytic capacitor that does not have the above-mentioned drawbacks.

Examples thereof will be described below with reference to the drawings. FIG. 2 shows a thin metal plate 7 for an anode external terminal used in the present invention. This metal thin plate 7 is made of a metal that can be welded to the tantalum anode lead wire of a tantalum solid electrolytic capacitor element, such as nickel, iron, stainless steel, etc., and has a thickness of 0.2w! n
A solder plating layer 8 with a thickness of about 10μ is provided on one side, and a surface layer 9 on the other side is sandblasted or copper plated to improve adhesion with resin. It is formed by subjecting this to a chemical conversion treatment. FIG. 3 shows a tantalum solid electrolytic capacitor element 10 of the present invention in which an anode chemical coating, a semiconductor layer, and a conductor layer are formed.
The figure shows a state in which tantalum anode lead wires 11 are bent at right angles and continuously arranged and welded to stainless steel loops 12 at regular intervals.

The reason why the lead wire 11 is welded to the loop 12 is to facilitate the arrangement and welding of the elements 10 on the thin metal plate 7 in the next step. FIG. 4 shows a state in which the elements shown in FIG. 3 are arranged in a grid pattern on the surface layer 9 of the thin metal plate 7 shown in FIG. 2, the anode lead wire 11 is welded, and the loop 12 is cut and removed. There is.

FIG. 5 shows the capacitor element 10 of FIG. 4 in which an anode lead wire 11 is welded to a thin metal plate 7 forming an anode terminal, and the capacitor element 10 is molded with resin 14 so that a portion 13 of the cathode is exposed. The resin used is an epoxy resin or the like, and a curing agent and a filler are mixed with this resin. The next step is to form an external cathode terminal, but this step is performed as needed and is not necessarily required.

One method is to pressurize the solder welded to the exposed part 13 of the cathode and level it. One method is to form the solder layer 15 by ring processing (FIG. 6A), and another method is to apply a conductive adhesive 16 to the exposed part 13 of the cathode, and then apply a metal plate 17 (copper plate) on top of the conductive adhesive 16. Or a method of bonding and forming brass plates (or solder-plated iron plates) A slicing machine with a diamond blade is used to cut and separate the material into predetermined dimensions.

Figure 7 is a cross-sectional view of the final chip-type solid electrolytic capacitor. Each figure shows the process that was carried out in the illustration. The method for manufacturing a chip-type solid electrolytic capacitor of the present invention includes a method of manufacturing a weldable metal thin plate of an anode lead wire, and a plurality of capacitor elements arranged at regular intervals in a metal loop between the anode lead wire and the metal thin plate. ) The anode lead wire is welded to the thin metal plate, and after removing the metal loop, a part of the cathode of the capacitor element is exposed and filled with resin. After the resin is cured,
This method involves cutting the thin metal plate filled with the resin into a grid shape to form individual chip-type solid electrolytic capacitors.

Therefore, by closely arranging a large number of capacitor elements on the thin metal plate that forms the anode terminal, it is possible to simultaneously manufacture a large number of chip-type solid electrolytic capacitors, and the process is extremely simple. It is possible to mass produce it at low cost. Furthermore, after the filled resin is cured, it is cut into a lattice shape using a cutter, which has the excellent effect of providing a chip-type solid electrolytic capacitor with constant shape and dimensions and stable quality.

[Brief explanation of the drawing]

Figure 1: A diagram showing a conventional chip-type solid electrolytic capacitor, where A is a resin mold type and a U-shaped terminal type. Figure 2: A perspective view of a thin metal plate used in the present invention. Figure 3: A perspective view of the capacitor element of the present invention, FIG. 4: A perspective view showing the state in which the capacitor element of FIG. 3 is placed on the thin metal plate of FIG. 2, FIG. 5: The capacitor element of FIG. 4 is filled with resin. Fig. 6: A side sectional view of the capacitor element in Fig. 5 after being filled with resin and subjected to cathode terminal processing. FIG. 7: A cross-sectional view of a chip-type solid electrolytic capacitor produced by the method of the present invention, in which A shows the case where no cathode terminal processing is performed. When the cathode terminal processing shown in Figure 6 A is applied, C is when the cathode terminal processing shown in Figure 6 is applied, [symbol], 1...
・Capacitor element, 2, 3... Metal piece, 4...
・Resin, 5... Cathode terminal, 6... Anode terminal, 7... Metal thin plate, 8... Solder plating layer, 9... Surface layer, 10... Capacitor element, 11... Anode lead wire, 12... Loop, 13... Part of negative 5, 14... Resin, 15 ...Solder layer, 16 ... Conductive adhesive, 17 ... Metal plate.

Claims (1)

[Scope of Claims] 1. A large number of capacitor elements are arranged at regular intervals in a metal loop on a weldable metal thin plate of an anode lead wire, and the anode lead wire and the metal thin plate are brought into contact with each other. After the anode lead wire is welded to the thin metal plate and the metal loop is removed, a part of the cathode of the capacitor element is exposed and filled with resin, and the resin is cured. A method for producing a chip-type solid electrolytic capacitor, which comprises: cutting the thin metal plate filled with the resin into a grid shape to form individual capacitors. 2. The thin metal plate is a nickel plate, iron plate, or stainless steel plate that can be welded to the tantalum anode lead wire of a tantalum solid electrolytic capacitor, and the surface on the side to be filled with the resin has good adhesion with the resin. 2. The method of manufacturing a chip-type solid electrolytic capacitor according to claim 1, wherein a surface layer is formed thereon, and a solder plating layer is formed on the opposite surface.